982 resultados para Boyd, Alan
Resumo:
The paper presents a new criterion for designing a power-system stabiliser, which is that it should cancel the negative damping torque inherent in a synchronous generator and automatic voltage regulator. The method arises from analysis based on the properties of tensor invariance, but it is easily implemented, and leads to the design of an adaptive controller. Extensive computations and simulation have been performed, and laboratory tests have been conducted on a computer-controlled micromachine system. Results are presented illustrating the effectiveness of the adaptive stabiliser.
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This thesis combines a computational analysis of a comprehensive corpus of Finnish lake names with a theoretical background in cognitive linguistics. The combination results on the one hand in a description of the toponymic system and the processes involved in analogy-based naming and on the other hand some adjustments to Construction Grammar. Finnish lake names are suitable for this kind of study, as they are to a large extent semantically transparent even when relatively old. There is also a large number of them, and they are comprehensively collected in a computer database. The current work starts with an exploratory computational analysis of co-location patterns between different lake names. Such an analysis makes it possible to assess the importance of analogy and patterns in naming. Prior research has suggested that analogy plays an important role, often also in cases where there are other motivations for the name, and the current study confirms this. However, it also appears that naming patterns are very fuzzy and that their nature is somewhat hard to define in an essentially structuralist tradition. In describing toponymic structure and the processes involved in naming, cognitive linguistics presents itself as a promising theoretical basis. The descriptive formalism of Construction Grammar seems especially well suited for the task. However, now productivity becomes a problem: it is not nearly as clear-cut as the latter theory often assumes, and this is even more apparent in names than in more traditional linguistic material. The varying degree of productivity is most naturally described by a prototype-based theory. Such an approach, however, requires some adjustments to onstruction Grammar. Based on all this, the thesis proposes a descriptive model where a new name -- or more generally, a new linguistic expression -- can be formed by conceptual integration from either a single prior example or a construction generalised from a number of different prior ones. The new model accounts nicely for various aspects of naming that are problematic for the traditional description based on analogy and patterns.
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Itämerensuomalaisissa kielissä esiintyy suuri joukko sanoja, jotka muistuttavat balttilaisten kielten sanoja sekä muotonsa että merkityksensä puolesta. Yhtäläisyyksiä oli yritetty selittää eri tavoin 1700-luvulta lähtien, kunnes Vilhelm Thomsen vuonna 1869 osoitti tämän sanastokerrostuman olevan lainaa jostakin muinaisbalttilaisesta kielimuodosta nykyisten itämerensuomalaisten kielten yhteiseen kantakieleen. Vuonna 1890 Thomsen julkaisi aiheesta laajemman tutkimuksen, jossa hän esitti noin 200 muinaisbalttilaista lainaetymologiaa ja käsitteli lainojen äännevastaavuuksia sekä kielellisten kontaktien paikkaa, aikakautta ja kulttuurikontekstia. Nykykäsitys itämerensuomalaisten kielten vanhoista balttilaisista lainasanoista perustuu tähän Thomsenin esitykseen, ainoastaan kontaktien ajoituksia on arkeologian tulosten myötä siirretty taaksepäin. Thomsen sovelsi ensimmäisenä suomalais-ugrilaisten kielten tutkimukseen aikakautensa uusinta kielitieteellistä metodia, nuorgrammatiikkaa. Nuorgrammatiikka keskittyi kielihistoriaan ja antoi eksaktit välineet etymologialle. Suomeen nuorgrammatiikan toi E. N. Setälä, jonka johdolla metodi uudisti nopeasti koko fennougristiikan ja nosti Suomen tutkimuksen kärkeen. Suomalaistutkijat tarkensivat myös Thomsenin luomaa kuvaa vanhoista balttilaisista lainoista. Setälän ohella keskeisiä etymologeja olivat J. J. Mikkola ja Heikki Paasonen. Muualla tutkimus ei ollut yhtä intensiivistä: vain liettualainen Kazimieras Būga perehtyi mainittavasti aiheeseen, ja hänenkin tutkijan uransa jäi lyhyeksi. Vasta 1910-luvun puolessa välissä Thomsenin ja Setälän teesejä alettiin kritikoida. Torsten Karsten ja K. B. Wiklund esittivät vanhimmille balttilaiskontakteille paljon kauemmas menneisyyteen ulottuvia ajoituksia kuin Thomsen. Setälän auktoriteetti kuitenkin torjui uudet teoriat, jotka on vasta paljon myöhemmin yleisesti hyväksytty. Sotien välinen kausi oli erittäin vilkkaan etymologisen tutkimuksen aikaa, ja balttilaisiakin lainoja esitettiin kymmeniä lisää. Ajan uutterimmat tutkijat olivat Heikki Ojansuu, Yrjö Toivonen ja Jalo Kalima. Luonnollisesti myös monet Thomsenin balttilaiset etymologiat korvattiin paremmin sopivilla lainaetymologioilla tai rinnastuksilla sukukielistä. Mikkola arvosteli hyvin voimakkaasti Thomsenin lainaetymologioita. Mikkolan kritiikki osoittautui pääosin pätemättömäksi, mutta on päässyt epäsuorasti vaikuttamaan myöhempään tutkimukseen. Eino Nieminen taas esitti vuonna 1934 hypoteesin, jonka mukaan ainakin osa vanhoista balttilaislainoista voisi olla peräisin muinaiskuurin kielestä, jota baltologit olivat parin vuosikymmenen ajan pyrkineet rekonstruoimaan. Jalo Kalima julkaisi vuonna 1936 oppikirjan itämerensuomalaisten kielten vanhoista balttilaislainoista. Kalima pyrki antamaan kattavan kuvan aiheesta, mutta ei onnistunut kovin hyvin. Kaliman tiedot balttilaisista kielistä eivät olleet ajan tutkimuksen tasolla, ja hän jätti kirjassansa käsittelemättä suuren osan uudempaa tutkimusta, mm. Thomsenin ajoituksia kohtaan osoitetun kritiikin sekä kymmenittäin niin Thomsenin kuin myöhempienkin tutkijoitten esittämiä etymologioita. Kaliman kirja on kuitenkin selkeästi laadittu ja sisältää uusia, ansiokkaitakin etymologioita. Kaliman jälkeen kukaan ei ole kirjoittanut yleisesitystä aiheesta. Tämän tutkielman tavoite on antaa kattava kuva vanhimpien itämerensuomalais-balttilaisten kielikontaktien tutkimuksesta ennen Kaliman oppikirjaa. Näin se voisi tasoittaa tietä uudelle alan yleisesitykselle.
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The Australian government has recognised the importance of early childhood education and care (ECEC) in recent years. With over one million Australian children accessing early childhood education provision every day (Productivity Commission, 2014), today’s children are a generation who spend a large part of their early years in some form of out-of-home child care. Early chapters in this text have discussed a range of people, theories and approaches that inform the development of ECEC. Early childhood pedagogical practice is an eclectic mix of these ideas. This chapter begins with an overview of the ways young children learn in early childhood education, highlighting play-based learning as a pedagogical response to our understandings about children. Next the chapter outlines areas that have more recently influenced ECEC including international models of early childhood education, neuroscience, studies of young children, economic research and social justice principles. Drawing on the reflections of educators working in various ECEC contexts, the chapter then presents four topics encountered by educators as part of their everyday work with diverse communities. These topics include: • the educational program for children in the early years • relationships and partnerships with diverse families • professional accountabilities, and • changing constructions of childhood.
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Australian perspectives and practices within early childhood education and care are underpinned by understandings of children, how they learn, their emotional and physical needs and their connectedness to family and their communities. There is strong international research evidence supporting the value of providing high quality and accessible early childhood education and care, and this evidence base continues to grow. Drawing on international and Australian research, this book provides an introduction to this complex and multifaceted field.
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24-norursodeoxycholic acid (norUDCA), a side chain-modified ursodeoxycholic acid derivative, has dramatic therapeutic effects in experimental cholestasis and may be a promising agent for the treatment of cholestatic liver diseases. We aimed to better understand the physiologic and therapeutic properties of norUDCA and to test if they are related to its side chain length and/or relative resistance to amidation. For this purpose, Mdr2-/- mice, a model for sclerosing cholangitis, received either a standard diet or a norUDCA-, tauro norursodeoxycholic acid (tauro- norUDCA)-, or di norursodeoxycholic acid (di norUDCA)-enriched diet. Bile composition, serum biochemistry, liver histology, fibrosis, and expression of key detoxification and transport systems were investigated. Direct choleretic effects were addressed in isolated bile duct units. The role of Cftr for norUDCA-induced choleresis was explored in Cftr-/- mice. norUDCA had pharmacologic features that were not shared by its derivatives, including the increase in hepatic and serum bile acid levels and a strong stimulation of biliary HCO3- -output. norUDCA directly stimulated fluid secretion in isolated bile duct units in a HCO3- -dependent fashion to a higher extent than the other bile acids. Notably, the norUDCA significantly stimulated HCO 3- -output also in Cftr-/- mice. In Mdr2-/- mice, cholangitis and fibrosis strongly improved with norUDCA, remained unchanged with tauro- norUDCA, and worsened with di norUDCA. Expression of Mrp4, Cyp2b10, and Sult2a1 was increased by norUDCA and di norUDCA, but was unaffected by tauro- norUDCA. Conclusion:The relative resistance of norUDCA to amidation may explain its unique physiologic and pharmacologic properties. These include the ability to undergo cholehepatic shunting and to directly stimulate cholangiocyte secretion, both resulting in a HCO3- -rich hypercholeresis that protects the liver from cholestatic injury.
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This study deals with the formation of the idea of research and development (r&d) activity at one particular university of applied sciences in Finland. In this study I proceed from examining the conceptions of management regarding r&d-activities to exploring the development of the complex concept that guides these r&d-activities. The aim of this study is, first, to describe conceptions of r&d-activities, and then, second, to describe the formation of a new concept for r&d-activities in one field of study at the university of applied sciences. I used phenomenographic analysis to elucidate the conceptions and collected the data in interviews of personnel (22) who belong to the management of the university of applied sciences. The data for analysing the obstacles faced and the ways of overcoming them during the formation process of the new concept consist of the video-recorded material from ten change laboratory sessions held for the specific field of study at the university of applied sciences. In researching the formation of the concept of the activity, such research and analysis methods are used in which the concept is understood as a material construction, and with the help of which one can work out the formation of the concept during the development process. When the systematic development of the r&d-work was underway, the management of the university of applied sciences held differing views regarding the content, target, factors and organisation of the r&d-activities, as well as regarding the position of dissertations as a part of r&d-activity. Obstacles for developing rd concerned the unclear object and outcomes of the new activity, not having the tools (such as adequate know-how) for the new activity and not having found the necessary solutions for the distribution of work. In addition the rules that quide the activities of the university of applied sciences did not support working according to the new way. To improve r&d-activity, the school’s management defined three development strategies to encourage adequate rd-activity to support working life, regional development and learning. The strategies were based on the expansion of existing methods, such as service activities, dissertation work and the research activities of the teachers. Of the three possible routes, the concept of dissertation in this study was expanded to integrate the services of organisation development and the occupational growth of the students. A group of teachers in the field of social and health studies participated in the development work. The change laboratory method was used as a tool for this work. Analysis of the cognitive trails indicated that, in addition to the cycle of expansive learning activities, microcycles with different purposes can exist. According to Cussins (1992), something already in existence in each microcycle is destabilised, and something else is stabilised to replace it. In this study three microcycles were identified, during which the teachers first destabilised the existing concepts of dissertation work that guided their thinking, and then began to use new concepts to structure their thinking. Secondly, they undermined the existing concepts with material structure that defined their practical work, and developed new practical models to replace them. Thirdly, the problems accumulating in researching and testing the new activities caused the developers to destabilise the r&d-strategies of the university of applied sciences and to define a new conceptual model for r&d-work in the field. During this third cycle, the teachers developed a research arena model, which was a significant expansive innovation. In the cognitive trails developing the new concept for the r&d-activity, the teachers indeed faced the obstacles the management had described as their conceptions. These obstacles manifested themselves as contradictions. During the development process, the nature of the obstacles (i.e. contradictions) changed as the development proceeded. Solving the first and second degree contradictions highlighted the third and fourth degree contradictions. To overcome the obstacles, the teachers had to to articulate the value and motive of the development work throughout the development process. Developing the new concept for r&d-activity required many reconfigurations of practical solutions to overcome the obstacles. Developing the new concept for r&d-activity, both at the level of representations and of new practices, requires universities of applied sciences to adopt new methods in which the actors are partake in construction of new concepts of activity through adequate discussion, analysis and debate. R&d -activity can progress, if instead of implementing partial solutions, the totality of the activities (i.e. the group of partial solutions acting together) will be constructed. The development of the activity system requires many simultaneous changes as well as wide-ranging know-how and discussion related to these changes. What is perhaps most important, however, is that the group of developers mature into a determined collective actor which can engage in many agentive actions. The development of the agency is fundamental to progress.
Resumo:
Security models for two-party authenticated key exchange (AKE) protocols have developed over time to capture the security of AKE protocols even when the adversary learns certain secret values. Increased granularity of security can be modelled by considering partial leakage of secrets in the manner of models for leakage-resilient cryptography, designed to capture side-channel attacks. In this work, we use the strongest known partial-leakage-based security model for key exchange protocols, namely continuous after-the-fact leakage eCK (CAFL-eCK) model. We resolve an open problem by constructing the first concrete two-pass leakage-resilient key exchange protocol that is secure in the CAFL-eCK model.
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Design embraces several disciplines dedicated to the production of artifacts and services. These disciplines are quite independent and only recently has psychological interest focused on them. Nowadays, the psychological theories of design, also called design cognition literature, describe the design process from the information processing viewpoint. These models co-exist with the normative standards of how designs should be crafted. In many places there are concrete discrepancies between these two in a way that resembles the differences between the actual and ideal decision-making. This study aimed to explore the possible difference related to problem decomposition. Decomposition is a standard component of human problem-solving models and is also included in the normative models of design. The idea of decomposition is to focus on a single aspect of the problem at a time. Despite its significance, the nature of decomposition in conceptual design is poorly understood and has only been preliminary investigated. This study addressed the status of decomposition in conceptual design of products using protocol analysis. Previous empirical investigations have argued that there are implicit and explicit decomposition, but have not provided a theoretical basis for these two. Therefore, the current research began by reviewing the problem solving and design literature and then composing a cognitive model of the solution search of conceptual design. The result is a synthetic view which describes recognition and decomposition as the basic schemata for conceptual design. A psychological experiment was conducted to explore decomposition. In the test, sixteen (N=16) senior students of mechanical engineering created concepts for two alternative tasks. The concurrent think-aloud method and protocol analysis were used to study decomposition. The results showed that despite the emphasis on decomposition in the formal education, only few designers (N=3) used decomposition explicitly and spontaneously in the presented tasks, although the designers in general applied a top-down control strategy. Instead, inferring from the use of structured strategies, the designers always relied on implicit decomposition. These results confirm the initial observations found in the literature, but they also suggest that decomposition should be investigated further. In the future, the benefits and possibilities of explicit decomposition should be considered along with the cognitive mechanisms behind decomposition. After that, the current results could be reinterpreted.
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Conducting and semiconducting polymers are important materials in the development of printed, flexible, large-area electronics such as flat-panel displays and photovoltaic cells. There has been rapid progress in developing conjugated polymers with high transport mobility required for high-performance field-effect transistors (FETs), beginning(1) with mobilities around 10(-4) cm(2) V-1 s(-1) to a recent report(2) of 1 cm(2) V-1 s(-1) for poly(2,5-bis(3-tetradecylthiophen-2-yl) thieno[3,2-b] thiophene) (PBTTT). Here, the electrical properties of PBTTT are studied at high charge densities both as the semiconductor layer in FETs and in electrochemically doped films to determine the transport mechanism. We show that data obtained using a wide range of parameters (temperature, gate-induced carrier density, source-drain voltage and doping level) scale onto the universal curve predicted for transport in the Luttinger liquid description of the one-dimensional `metal'.
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Chromolaena, or Siam weed, is a serious problem in several tropical and sub-tropical areas around the world. In our own region, it is a serious weed in New Guinea, East Timor and Indonesia and is also under an eradication regime in North Queensland. The chapter summarises current knowledge about the taxonomy, biology, distribution, ecology, impacts and control of the weed. Biological control has been a major multinational initiative against this weed in recent years and these efforts are described in some detail. Interestingly agents have not been universally effective because of weed biotype differences and climate. Considerable success has been achieved in New Guinea, principally with the tephritid fly Cecidocares connex and by the efforts of Michael Day, Rachel McFadyen and Graham Donnelly from Alan Fletcher Research Station.
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Tietotekniikan kehittyessä lisääntyy sekä tietotyön tekijöiden tarve että paine tehostaa opetusta tietotekniikan avulla. Tietotyöläisten tarvitsemien taitojen opettamiseen tarvitaan uutta pedagogiikkaa, jossa korostetaan tietojen ja sääntöjen seuraamisen sijaan taitoja, itsenäisyyttä ja oppimaan oppimista. Tietotekniikankäyttäminen opetuksessa tuo omat haasteensa oppimistilanteisiin. Sosiokonstruktiivinen, yhteisöllinenverkko"-oppiminen onkin nousemassa perinteisen opettajajohtoisen opetuksen haastajaksi. Suomessa kehitetty Tutkiva oppiminen on yksi tämän viitekehyksen mukaisista pedagogisista menetelmistä. Koska sosiokonstruktiivinen teoria korostaa ihmisten välisiä suhteita yli yksittäisen ihmisen toiminnan, alan tutkimuksenkin on otettava kantaa tutkimustilanteessa esiintyviin vuorovaikutussuhteisiin. Tähän perinteiset psykologiset ja pedagogiset menetelmät eivät sovellu, kun taas sosiaalitieteissä suhteellisen vanha analyysimenetelmä, SVA eli sosiaalinen verkostoanalyysi, on tarkoitettu nimen\-omaan ihmisryhmien analysoimiseen. SVA:n sovellukset psykologian ja yhteisöllisen oppimisen alueilla ovat kuitenkin vasta alustavia, eikä luotettavaa näyttöä menetelmän soveltumisesta saatika hyödyllisistä tuloksista vielä ole. Tämän tutkimuksen on tarkoitus selvittää, onko SVA sovellettavissa tälle tutkimuksen alueelle. Tässä tutkimuksessa SVA:ta käytettiin 23 peruskoulu- ja lukioluokan Tutkivan oppimisen menetelmällä toteutettujen oppimistilanteiden tutkimiseen. Tulokset osoittavat, että SVA soveltuu yhteisöllisen verkko-oppimisen tutkimiseen, sillä tästä aineistosta löytyi alustavia SVA:n tunnuslukuja, jotka ovat yhteydessä oppimistilanteen laatuun. Tulokset ovat myös pitkälti sosiokonstruktiivisen teorian mukaisia: kurssin hyöty nousee, kun useat oppilaat kirjoittavat korkealaatuisia viestejä ja osallistuvat kattavasti eri keskusteluihin. Avainsanat: Tutkiva oppiminen, sosiokonstruktivismi, pedagogiikka, yhteisöllisyys, yhteisöllinen verkko-oppiminen, Fle3, SVA, sosiaalinen verkostoanalyysi, koulu, opetus.
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Starting point for the study was the notion made in previous studies that the Finnish educational practices are not sufficient in multicultural teaching. The main objective of the research was to find out good multicultural teaching practices developed by experienced teachers. The subject of the research was teachers narratives about the problems, solutions and the development of multicultural academic teaching. Previous research has shown that disturbances in multicultural activity can be caused among other things by cultural and linguistic differences, racism and prejudice and stress related to immigration. The management of multicultural teaching can be examined from the individual point of view as intercultural competence and from the collective point of view as management of the disturbances of multicultural teaching. The development of the management has been illustrated with the models of adaptation and transformative/expansive learning. The methodological approach of the research was narrative. I interviewed six teachers with narrative methods. Half of the interviews were pair interviews. As an analytical framework I used the basic story model by Labov (1972). I analysed critical incidents, resolutions and evaluations of the stories. According to the results the problems of the multicultural academic teaching are diverse. Most often mentioned problems were cultural differences and racism. Problems were managed by developing practices that support the multicultural activity broadly and by reacting to sudden problems intuitively or reflectively. In the management of the academic multicultural teaching the experienced teachers emphasised flexibility, group building and trust, intensified guidance, acting against racism and prejudice and characteristics of the teacher, like patience and sense of humour. The management of multicultural teaching has developed through the accumulation of intercultural experiences, reflection of experiences, cooperative problem solving, following the research of the field and experimenting different approaches. In accordance with the previous studies, this research showed that continuous learning is needed in the management of multicultural teaching. The results can be used in developing academic multicultural teaching and education.
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Landscape and local-scale influences are important drivers of plant community structure. However, their relative contribution and the degree to which they interact remain unclear. We quantified the extent to which landscape structure, within-patch habitat and their confounding effects determine post-clearing tree densities and composition in agricultural landscapes in eastern subtropical Australia. Landscape structure (incorporating habitat fragmentation and loss) and within-patch (site) features were quantified for 60 remnant patches of Eucalyptus populnea (Myrtaceae) woodland. Tree density and species for three ecological maturity classes (regeneration, early maturity, late maturity) and local site features were assessed in one 100 × 10 m plot per patch. All but one landscape characteristic was determined within a 1.3-km radius of plots; Euclidean nearest neighbour distance was measured inside a 5-km radius. Variation in tree density and composition for each maturity class was partitioned into independent landscape, independent site and joint effects of landscape and site features using redundancy analysis. Independent site effects explained more variation in regeneration density and composition than pure landscape effects; significant predictors were the proportion of early and late maturity trees at a site, rainfall and the associated interaction. Conversely, landscape structure explained greater variation in early and late maturity tree density and composition than site predictors. Area of remnant native vegetation within a landscape and patch characteristics (area, shape, edge contrast) were significant predictors of early maturity tree density. However, 31% of the explained variation in early mature tree differences represented confounding influences of landscape and local variables. We suggest that within-patch characteristics are important in influencing semi-arid woodland tree regeneration. However, independent and confounding effects of landscape structure resulting from previous vegetation clearing may have exerted a greater historical influence on older cohorts and should be accounted for when examining woodland dynamics across a broader range of environments.